The reasons why I do not wish to split the static images on multiple subdomains is because, the images will load random. If I have 1 to 20 images and I add multiple subdomain for the images on a slow connection it will load like this (1 9 2 20 18) as to where I would have one single subdomain. With one subdomain they loading is progresive, it will load the first 4 and then the next 4 and so one. I might implement lazyload later.

I did fix the css errors and used html strict (with a few errors still displaying) I did not see any improvment for the start render. I have not tested to see if the domContentLoaded is faster, which I'm guess it is, I'm to lazy to revert back and to test it.

My server speed is around ~ 2MB/s. I'm also using couldflare, which adds more to TTFB but it's worth if for the cdn. Also did anyone tested the cloudflare railgun? I'm curios to how much would it reduce TTFB. I can't seem to find any real test done

Also I did not know that //,% was not permited in element id, again thank you all for the tips

Yes I tested and found the sub-domains would not help. That was a "tip" I picked up in a W3C course and di not think it through. I have since done a lot of testing on your page. I created a similar page with 48 thumbnails (you have 44) with sizes from 5K to 15KBytes (larger than yours) and got the page to load in 0.500 - 0.700 seconds.